This invention relates in general to the field of detonators, and generally to the detonation of any of a variety of devices by means of a strictly controlled explosive reaction.
Prior to the development of the present invention, detonators having a delay column have sometimes provided inconsistent delay periods and misfires believed to be due to incomplete, channelled and non-uniform combustion patterns down the length of the column.
It is, therefore, an object of the present invention to provide a delay detonation device for use in a wide variety of military and civilian applications.
It is a further object of the present invention to provide such a detonator which, as required for many applications, is characterized by a precise delay period between ignition and output.
It is also an object of the present invention to provide a delay detonator which is characterized by a delay column which substantially entirely accounts for the contribution of burn time comprising the detonation period.
It is a further object of this invention to provide a delay detonator wherein the period between ignition and output, being essentially entirely attributable to the delay column, is predictably and precisely controllable and variable by means of adjustments in the dimensions of the delay column.
Another object of the present invention is to provide a delay detonator with a delay column characterized by a high length/diameter aspect ratio and a precisely uniform, controlled combustion pattern which thereby provides consistently and accurately predictable and predetermined delay periods.
Briefly, this invention provides a delay detonator for causing output device detonation a predetermined delay period of time following ignition of the detonator. The detonator comprises a metal body, a primer fitted at an inner end of the body, a recess opening from the primer into an expansion chamber, a first-fire combustion section including first-fire ignition powder separated from the expansion chamber by a retention screen, a delay column proximate the first-fire combustion section including a delay powder composition to be ignited by the ignition powder, the delay column being of a relatively high length/diameter aspect ratio, a further combustion section including first-fire ignition powder for ignition by the delay column after a delay burn time thereof, and a detonator output assembly at the opposite, outer end of the body for ignition by the further combustion section.
Still further objects and features of the present invention will emanate from the drawings, description and claims.